A Comprehensive Approach to Preventing Tauopathy and Enhancing Learning and Memory through Neurotrophic Factor Induction with Cistanche tubulosa Extract

The neuroprotective efficacy and safety of Cistanche tubulosa extract (CTE) in reducing tauopathy levels were studied. However, evidence-based insights into how CTE enhances memory ability remain unclear. A total of 85 healthy volunteers (with MMSE scores ≥ 24, which is Normal/No impairment) participated in a double-blind, randomized, placebo-controlled study. Participants were assigned to one of three groups: Group A (600 mg CTE), Group B (300 mg CTE), or Group C (placebo), administered once daily for six weeks. Efficacy was assessed using the clinical memory scale, along with measurements of brain-derived neurotrophic factor (BDNF) and acetylcholinesterase (AChE) concentrations. Results showed statistically significant changes in BDNF and AChE levels in both treatment groups (Groups A and B) compared to baseline and the placebo group. Memory tests also demonstrated significant improvements (p < 0.01) in summary test scores in Groups A and B compared to Group C after six weeks. Additionally, we utilized the Tol2 transposon-mediated gene transfer method to generate transgenic zebrafish expressing tau-GFP (green fluorescent protein), and employed CTE compounds (echinacoside, acteoside, and isoacteoside) to screen for anti-secretase enzyme activity. Results from transgenic fluorescent triple-transgenic (3xTg-AD) zebrafish demonstrated that CTE exhibits anti-tauopathy, anti-secretase, and neuroprotective properties. These findings, combined with the above evidence, confirm that CTE has potential neuroprotective effects and may improve memory function.